sunray

Personally I'd rather have food.

Hopefully a picture speaks a thousand words. Half wave rectificationwith 2 diodes in series with one reversed. No current can flow in either polarity: Solution: reverse the load: I recall this problem cropped up a lot of years back on some model railway points motors where different manufacturers opted for the opposite polirity and therefore incompatible.

Going back 25 years I was in this position, a mobile disco CO-OP brought in 4 with blown bulbs, they were 1*15" 400W, 2*12" 250W, 4* tweeter (3" ?) all Celestion & 4*piezo. Marron carpet & grill covered. The tweeters and piezo were protected by 2 festoon bulbs (2 tweeters and 2 piezo per bulb IIRC). Luckily they had more similar speakers, I wired one of their good bulbs in series with all ratings of festoons available from an automotive outlet and did a simple comparison on a variable supply measuring the voltage across each bulb. 12V 18W was the closest match. I used to keep a stock of 24V 45W bulbs for Bose 802's (then 12V 12W when the 45's became unavailable) where so many used to come in but they are a very different beast.

Indeed. In 1969 I used a valve amplifier (ECC81 & PL84) and loudspeaker robbed from a record player, LT & HT PSU's from physics dept, headset from language lab for comms between MD (Known as organist) and lighting. I soon added c/o switch to isolate LS and enable Foster DF1 microphone to talkback to MD. used for 2 plays a year apart. After leaving school I joined a little theatre club and installed the same system into there for use between SM/sound position to lighting but knocked up a basic PSU, changed the PL84 to EL84 and the C/O switch to PTT button and used the LS as the talkback mic. I did 2 plays there as lighting op and left it in place. About 10 years later I went to a show and it was still in place and lit so I assume being used.

I've done this several times with a half coupler or hook clamp and 1/4"W bolt, 2 penny washers, nut and wing nut As mentiined adding a ball joint will make things much easier

If it's a 6th form college there are likely to be technical students with contruction abilities. Look on this forum for blueclone.

This sort of sleeving makes a good multicore https://www.ebay.co.uk/itm/175821632523?var=475224440614&itmmeta=01HVMD1FW5CW4TMA1EKRXBBY9V&hash=item28efc9340b:g:8XEAAOSwaxBktPWf&itmprp=enc%3AAQAJAAAA4O83tJaNvCmVhFZdXqXoVTLD5OAq6aCfYLqo1hbc2tgFXN%2FqVQVFdJvosaVxeYzcCeR8uwqiFGe8%2BF2oFUkwAJSjSGpzjqV8hAFzBOeI6z2EFntnMKxr43Lf5xEoInaS4PxXBY8IVA1H%2BLO3eqmfty9ZPtTzmDWJaLNJHLjDIcx19cX2j68Y1hq%2F0ITC5HZSodc3PO%2FVzvyu%2BeepxQZ4ppDgGZjqrKDPzU94ffRdx9BOpY1Vii1Tq8wZH7aHNSucMhy0nP1R09HFbZPpPFJRYKh8hMQ3BXQA5SjXZyZTXjCD|tkp%3ABFBMsv6Fjd1j I often position radiomic receivers nearer to the source rather than run long aerial cables. Bear in mind you will require a working space of at the very least the length of any loom you make, I've found it's easier to draw the sleeving onto the bunch of cables rather than pull them into the sleeve in which case you require twice the length. The longest I've done has been 50m, that requires at least 3 people but the end result is worth it.

I have no problems with the operation if they are individual & isolated, however to date I've only encountered them in groups of 4, 6 etc and so far only a common pin, I made up a cable just a couple of weeks back, DB25 (with only one common) to 4x 8 pin Din (with one common each) which is typical of what I've come across and until now assumed it's standard..

How does that work?

I've had involvement with wireless DMX twice, one was the issue of sequencing the start-up routine to revent them going into transmit and we had to replug mains services to achieve that however after that we found the system, and the other had the same issue, developed delay issues when the venue filled up, at a scene change there were some, but not always, obvious delays between the cabled fittings and those on wireless links and also odd flickers. One of them had 3 significant glitches coinciding with the goals scored in a football match which was the clincher for us.

I find with many things like this it's not worth making your own... But of course that's how I've always done it. A little while ago I installed 16XLR audio tiepairs between stage and control desk in a school hall. It was just cheaper to buy a ready made snake from CPC than to buy just the 16 way cable.

it was common to use 4 cat 5's in an overall sheath to simplify structured cabled ethernet but sadly not flexible. I used to use 7 pair stranded cat 5 a fair bit, we used to get it on 500m drums and behaved itself for portable work, even the overall braided screen version. It's possible I may have some offcuts lurking but doubt anything long. I don't see why larger sizes should not be available.

Absolutely. For years I've been using cat2 onwards for balanced audio and some very long runs, For OB's it's been common to use 2 pairs for stereo feed, 1 pair for return audio & 1 pair for talkback, sometimes as the actual link but more usually as the run between studio/radio and OB/radio and they may often be hundreds of metres. Years ago I made up some boxes with 4 XLRs and RJ45 for 'stage snake' type use then added a switch to some to use pair 4 as the common ground for phantom use. Just recently I repurposed a male end which was simply 4 thin FSTs style terminated in a RJ45 plug and male XLRs.

I started looking after I'd posted yesterday, I see a selection of models, are there any better/worse than others? The usual camera I've been using for a long while was a pretty good CCTV camera 20 years ago, I think about 350TVL and TBH most of what its used for the momentary white/black out doesn't really matter that much unless there is significant flashing. As I'm claiming to have retired I'm not looking to invest much😉

Cleared a shelf today, these bits are going on ebay tomorrow (Monday) PM while I have 80% offer Soundcraft power supply - CPS 150 Alice Matchpak X2 Canford twin microphone pre-amp Tannoy TX1 system controller Kramer FC10 Composite/YC transcoder Drake 1U IEC 10 way power distro - 10A max with 5m mains lead and 16A CEEform SCV universal balanced/unbalanced interface - includes: 3* VCA/AGC (unbalanced), 5* in/out, 1* 4unbal in to 2balanced out, 1*PSU Most unused since my last OB >10 years ago, just done very basic tests to confirm working and all have scratches from a working life. Open to offers.